Langenkamp later starred in Nickel Mountain (1984) which gained mostly positive reviews. While she was studying at Stanford University, Langenkamp rose to prominence when Wes Craven cast her as teen heroine Nancy Thompson in the hugely successful A Nightmare on Elm Street, the first film in the series as he wanted someone very 'non-Hollywood' to play Nancy. He believed that Langenkamp met this quality.[9] For the part she beat out more than 200 actresses.[10] The film follows the story of a group of teenagers who are killed in their dreams one-by-one by a supernaturalserial killer. The film was a slasher film. This film is credited for launching her career.

In between starring roles, she played Marie Lubbock on the television series Just the Ten of Us, which received critical acclaim and has gained a cult following. It was a spin-off of the popular situation comedy Growing Pains (on which Langenkamp guest-starred), from 1988 to 1990. That same year, she and her castmates were nominated for a Young Artist Award for Best Young Actor/Actress Ensemble in a Television Comedy, Drama Series or Special. She has also made numerous other guest appearances on television. In 1989, she had a cameo role as a victim in Wes Craven's Shocker. The film was a moderate commercial success despite negative reviews. Craven intended for Shocker to launch a new franchise but due to negative reviews and a middling box office performance, plans for a sequel were quickly dismissed.[14]

In 1994, Langenkamp returned to the A Nightmare on Elm Street franchise when she starred as herself in the critically and commercially successful film Wes Craven's New Nightmare alongside Robert Englund. Although New Nightmare is the seventh film in the A Nightmare on Elm Street franchise, it is not part of the series continuity, instead portraying Freddy Krueger as a fictional movie villain who invades the real world and haunts the cast and crew responsible for his films. While the canon Nightmare on Elm Street films are about dreams overlapping reality, this film is about films overlapping reality. In this film, Freddy is depicted as closer to what Craven originally intended, being more menacing and less comical, with an updated attire and appearance. Over the years, New Nightmare has often been referred to as the prelude to Scream, which went on to become a huge success.

Many elements of the plot for Wes Craven's New Nightmare are based on an incident in which Langenkamp received numerous threatening letters from an obsessed fan after the cancellation of Just the Ten of Us.[19]